A nickel-hydrogen secondary battery is frequently mounted as a secondary battery used in an electric vehicle or a mobile device. In recent years, a lithium ion battery has been developed as a secondary battery capable of further increasing output and capacitance, and is about to be put into practical use.
In a lithium ion battery, a multiple metal oxide containing lithium is used as the positive electrode, a material capable of storing and releasing lithium such as carbon is used as the negative electrode, and the materials are impregnated with an electrolytic solution made up of a lithium salt capable of dissociating ions and an organic solvent capable of dissolving the lithium salt (refer to PTL 1 or the like).
Since the electrolytic solution is a liquid having a possibility of liquid leakage, and the use of a combustible material demands an improvement of the safety of the battery in case of erroneous use, an all-solid-state lithium secondary battery in which a solid electrolyte is used instead of the electrolytic solution also has been disclosed (refer to PTL 2 or the like).
Since lithium that is a rare metal is used, the cost of the lithium ion battery increases, and there is a demand for a secondary battery having an additional increase in performance and capacitance in terms of performance.
In consideration of the above-described circumstances, the present inventors propose an all-solid-state semiconductor battery capable of reducing the cost and performing stable operation using a simple configuration (hereinafter referred to as quantum battery) (PCT/JP2010-067643).
The quantum battery is configured by laminating a substrate, a conductive base electrode, a charging layer that forms an energy level in the band gap through a photo-excited structural change of an n-type metal oxide semiconductor coated with an insulating substance and traps electrons, a p-type semiconductor layer and a conductive opposite electrode. The charging layer is charged by connecting a power supply between the base electrode and the opposite electrode.
For the above-described quantum battery, evaluation is made on the current-voltage characteristics and the charging and discharging characteristics that are required to check functions in a manufacturing process thereof.
It is known that the current-voltage characteristics are generally used as a method for evaluating the characteristics of a semiconductor, but the current-voltage characteristics are also applied to the performance evaluation of a secondary battery.
For example, the current-voltage characteristics are applied to a method in which an internal resistance is detected based on the measured values of the voltage and current of a battery for a hybrid vehicle during discharging and charging, and the accurate current-voltage characteristics of the battery are assumed, thereby detecting an accurate internal resistance of the battery (refer to PTL 3 or the like) or a method in which the output range of a battery is divided into multiple ranges, a set number of sets of voltage and current are measured for each range, the current-voltage characteristics of the battery are specified based on the measured values, and the maximum output of the battery is computed on the basis of the current-voltage characteristics (refer to PTL 4 or the like).
In addition, during the manufacturing of a quantum battery, since the performance of a secondary battery relies on the charging layer, the quantum battery can be efficiently manufactured by evaluating the charging layer in the middle phase in which the charging layer has been laminated in the manufacturing process rather than by evaluating the charging layer after manufacturing a finished product.
Evaluating functions in the middle phase of the manufacturing process is means in a semiconductor field, and, for example, there is a measurement apparatus provided with an exposed source electrode for measurement and an exposed drain electrode for measurement between both sides of a gate electrode for measurement coated with an insulating film which is intended to directly measure the electrical characteristic of a semiconductor serving as an active layer without actually producing a field-effect thin film transistor.
When the respective exposed surfaces of the source electrode for measurement, the drain electrode for measurement and the insulating film therebetween are brought into contact with the surface of the semiconductor, coplanar pseudo field-electric thin film transistors are constituted of the contact portions. Then, it is possible to carry out the same measurement before the production of elements as in a case of an ordinary coplanar field-electric thin film transistor in which the elements have been produced (refer to PTL 5 or the like).
In addition, a method in which the current-voltage characteristics are accurately measured using a pseudo MOSFET when evaluating a SOI substrate, and values with favorable reproducibility are obtained with the influence of changes over time reduced to the minimum extent (refer to PTL 6 or the like) or a semiconductor probe for measurement (refer to PTL 7 or the like) have been also proposed.